package com.wc.alorithm_luogu.P5015;

import java.util.Scanner;

/**
 * @Author congge
 * @Date 2023/4/22 15:01
 * @description
 */
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        String s = sc.nextLine();

        char[] chs = s.toCharArray();
        int ans = 0;

        for (char ch : chs) {
            if (ch>='a'&&ch<='z'){
                ans++;
            }else if (ch>='A'&&ch<='Z'){
                ans++;
            }else if (ch>='0'&&ch<='9'){
                ans++;
            }
        }

        System.out.println(ans);
    }
}
